The purpose of this study is to investigate dyeing properties of wool fabric with walnut colorants. Walnut colorants were extracted with water from walnut hull and characterized by FT-IR analysis. Effects of dyeing conditions and mordanting on dyeing properties and colorfastness were studied. Results obtained were as follows, 1. Higher K/S value was obtained at higher temperature and longer dyeing time, the highest K/S value was shown at $100^circ{C}$, 60min. 2. Dye uptake was increased with the increase in colorants concentration up to 2%. Higher K/S value was obtained at acidic condition. 3. Mordanting was not effective for improving dye uptake and colorfastness and for changing color of the dyed fabric.